Alam, M., Jaiswal, A., Agarwal, J., Yadav, K. et al., "Experimental Analysis of Retarding the Spark Timing in a Hydrogen Enriched Gasoline and Alcohol Blend Powered Spark Ignition Engine," SAE Technical Paper 2016-01-1277, 2016, doi:10.4271/2016-01-1277.
Gasoline has been the major fuel in transportation, its good calorific value and high volatility have made it suitable for use in different injection methods. The drastic increase in use of carbon based fuels has led to increase in harmful emissions, thus resulting in implementation of stricter emissions norms. These harmful emissions include carbon monoxide and NOx. To meet the new norms and reduce the harmful emissions, better techniques have to be implemented to achieve better combustion of gasoline and reduce the amount of carbon monoxide in the exhaust. One such way of doing this is by enriching gasoline with hydrogen. Due to its low activation energy and high calorific value, the high energy released from hydrogen can be used to achieve complete combustion of gasoline fuel. However, there are certain drawbacks to the use of hydrogen in spark ignition engine, knocking and overheating of engine parts being the major problems. The paper deals with the problems caused when hydrogen is used in spark ignition engine, this is done by varying the spark timing around the TDC and studying the effect on power output and emissions. The spark is varied through an external controlling unit. Concentration of CO decreases and an increase of NOx is observed by the enrichment, torque and NOx emissions are increased while an increase of CO concentration is observed by retarding the spark.